BTW, you can recover some files from a formatted partition. See e.g. PhotoRec. There are also more powerful proprietary tools that can recover pretty much everything including directory structure. That said WHY?
I just did this on 12.04. I chose ext4 in the Edit partition dialog box. I noted that the format box was unchecked. I ticked OK. The format box was in the "Install" dialog was STILL unchecked. I hit "Install Now". The precise moment I pressed "Install Now" it added a tick in the "Format?". I quickly tried to stop the install, but by the time I had it had already been formatted.
As I understand Ubiquity has a two second delay before it adds the tick to the "Format?" column; this allows the user to check twice (i.e in both dialogs) that the format box hasn't been checked, and still have their partition formatted under them.
BTW, you can recover some files from a formatted partition. See e.g. PhotoRec. There are also more powerful proprietary tools that can recover pretty much everything including directory structure. That said WHY?
I just did this on 12.04. I chose ext4 in the Edit partition dialog box. I noted that the format box was unchecked. I ticked OK. The format box was in the "Install" dialog was STILL unchecked. I hit "Install Now". The precise moment I pressed "Install Now" it added a tick in the "Format?". I quickly tried to stop the install, but by the time I had it had already been formatted.
As I understand Ubiquity has a two second delay before it adds the tick to the "Format?" column; this allows the user to check twice (i.e in both dialogs) that the format box hasn't been checked, and still have their partition formatted under them.